1. Field of the Invention
This invention relates to primer paints having an unusual, improved rheology that allows them to be applied at high, uniform film thickness with excellent coverage of sharp edges. They provide excellent protection against corrosion even when applied to rusted steel which has been only marginally prepared. The paints, for example, may be used on exposed large tanks for the reception of a topcoat reducing the amount of labor needed.
2. Prior Art
Johnson U.S. Pat. No. 2,858,285 discloses barium soaps, such as the lanolate, in corrosion-inhibiting paints based, for example, on alkyd resins.
Swanson U.S. Pat. No. 3,136,653 and Simon U.S. Pat. No. 4,232,090 illustrate some prior art primer coatings.
Madison U.S. Pat. No. 3,408,318 and Ginsberg et al U.S. Pat. No. 4,239,539 show comminuted metallic zinc in some coating materials.
Krueger U.S. Pat. No. 4,156,678 shows hydroxylated (meth)acrylic random copolymers, interpolymers, and polyisocyanates useful in the invention. Krueger's ultimate products, furthermore, make excellent topcoats for the instant primers.
Strolle et al U.S. Pat. No. 4,281,078 (Strolle) shows hydroxylated random copolymers prepared by copolymerizing at least one hydroxyalkyl ester of acrylic or methacrylic acid with at least one other ethylenically-unsaturated monomer and polyester polyols with methods for their preparation and organic polyisocyanates.
H. T. Dickman, "Organic and Inorganic Binders in Zinc-Rich Coatings", Modern Paint and Coatings, Vol 73, No. 3, pp. 32-38 (March 1983), discloses test results on some zinc-containing coatings.
All of the above art is specifically incorporated by reference herein.